Operation of internal-combustion engines with gas generators



E. SCHIMANEK OPERATION OF INTERNAL-COMBUSTION ENGINES WITH GAS GENERATORS Aug: 145 1945.

Filed Sept. 9, 1940 2 Sheets-Sheet 1 Aug. 14 1945. E. SCHl MANEK 2,332,747

r OPERATION OF INTERNAL-COMBUSTION ENGINES WITH GAS GENERATORS Filed Sept. 9, 1940 2 Sheets-Sheet 2 12 2/6/72? 5 1 16 m me Patented Aug. 14, 1945 OPERATION OF INTERNAL-COMBUSTION ENGINES WITH GAS GENERATORS Emil Schimanek, Budapest, Hungary; vested in the Alien Property Custodian Application September 9, 1940, Serial N 0. 356,072 In Germany May 23, 1940 Claims.

The usual internal combustion engines with gas generators have the drawback that the calorific power of the gas varies considerably with the quantity of gas consumed. If the motor runs at slow speed or with low output, the gas consumption is materially less than with high speeds and high outputs. With the known generators this results in a decrease of the gas velocity in the generator if the gas consumption is low whereby the height of the zone of incandescence in the generator decreases considerably.

As is well known, the quality of the gas depends upon theheight of the zone of incandescence in the generator through which the necessary air must flow. If new thehe-ight of the incandescence zone has decreased in consequence of the low gas consumption and afterwards because of a higher speed and a higher output of the motor, an increase of the gas consumption occurs, the increased quantity of air flowing through the generator With greater velocity will result in the combustionof the charge of the generator to CO2 instead of to CO in this zone of incandescence of too small height, whereby the calorific effect of the gas will be reduced materially. Sometimes this calorific effect will be reduced in this way to suchan extent that the motor will not run, even if the proportion of gas to the air in the mixture is kept constant. Furthermore the drawback occurs that with motors fed by generators also the proportion of gas to air in the mixture varies.

These drawbacks have the consequence that under different working conditions (different speeds and different outputs) the motor at least will not work with optimal conditions that is to say-the motor will not give the output and will not have the favorable consumption which it could have if the quality of the gas and the compo sition of the mixture could be kept constant. A change in the gas and in the composition results very often in serious disturbances. For instance if a vehicle descends a slope for a long period during which the motor works without load, the condition in the generator changes in view of the small quantity of gas consumed in such a manher that if afterwards the vehicle has to climb a hill of such a gradient that the motor could master it only if good gas and good mixture would be available, the output would be insufficient and that it would be necessary either to use benzene or the like until the condition of the generator would correspond to the high load, or to renew the incandescence in the generator with iii a ventilator or the like, it being necessary to stop the vehicle.

According to the invention these drawbacks are avoided by keeping practically constant the volume of air and/or gas and therefore also the velocity of flow of the air and/ or gas in the generator by varying the pressure in the generator at the different degrees of admission of the motor. According to the invention the pressure of the gas in the generator is varied by throttling the gas delivered by the generator, the control of the quantity of gas supplied to the motor being effected by controlling the air supply to the generator. 1

Hence, the invention enables to keep constant .the height of the zone of incandescence in the generator under all working conditions by control of the pressure dependent on the actual quantity' of gas required. If, for instance, the motor consumes less gas, the pressure in the generator is reduced so that the quantity of air and/or gas flowing through the generator per unit of time and therefore also the velocity of flow in the generator will be kept constant. Therefore, the air flowing through the generator will be in contact with the zone of incandescence in the generator during the same interval of time independent of the actual gas consumption whereby the quality of the gas will always be the same. I

If the motor always runs at the same speed, a certain effect may also be obtained by ar ranging the throttle (or the like) controlling the output of the motor, before the generator. If the throttle is, as commonly, arranged between the motor and the generator and influences the mixture, the pressure in the generator remains constant and the velocity of flow in the generator varies, whereas the arrangement of the throttle valve before the generator results in a variation of the pressure in the generator with the variation of the suction load. Since the motor under constant speed always sucks in the same volume of air per unit of time and with difierent loads only the pressure or the specific weight of the air sucked in or the like varies, the velocity of flow in the generator is kept constant with con- Slant Speed ly by the arrangement of the throttle valve before the generator.

If the motor works under ssure in the genin order to keep constant the velocity of flow in the generator.

According to the invention an adjustable throttling of the gas leaving the generator may be used, for instance in such a manner that a suitable throttling device will be closed more and more automatically with increasing speed of the motor by a regulating device or the like controlled by the speed. But also invariable throttle cross sections may be used because such throttle sections per so have a throttling eifect increasing with an increase of the gas consumption or an increase of the quantity of gas flowing'through the throttle. Thus, the increased volumetric suction effect of the motor will be balanced by the increase of the pressure in the generator. Throttling can be effectediin two or more steps.

According to the invention a constant gasair proportion of the mixture supplied to the motor can be obtained by feeding the air to the generator :and'the air to the mixing valve or the like, by means of apportioning devices which supply the .air to the generator and to the mixing valve in the proper proportion. the control of the degree of admission to the motor being effected by a throttle valve arranged before these devices. The correct proportion in the mixture, however, can he kept up also by the motor itself using a motor with multi-stroke working, supplying to the generator the air conveyed during the strokes which are not used for driving the motor. Ac-

cording to the .inventionfior instance, the motor works in a two-stroke cycle with supplemental pairs of strokes during which the air is fedto the generator. According to the invention the proportion of the mixture oi! gas and air may be controlled by throttling the suction during the supplemental pairs of strokes delivering the air to the generator. 1

The motor. of course, may work with a pinrality of supplemental :pairs of strokes and only a portion or the air delivered during the supplemental pairs of strokes could be fed to the generator whilst the other portion of the air may be fed tothemotor ascombustion air.

In order to improve the elasticity of themotor, according to the invention, the air is throttled before it enters the devices for apportioning the air, the throttling reducing the degree of admission to the motor at high speeds. tling may be efiected by aninvariable throttling section or by an adjustable throttling device controlled by a speed responsive regulating device, whereby with high speeds the degree of admission becomes lower than with low speeds, and therefore the elasticity o'ithe motor is improved.

The device for carrying out the process according to the invention comprises essentially one or more throttling sections arranged in the gas pipe leading from the generator to the motor and a throttling device arranged before the generator and being actuated arbitrarily to control the output. Advantageously the air pipes leading to the generator and to the motor are connected with one another in one pipe in which there is arranged the throttling device regulatlngthe output of the motor.

In the drawings different forms of execution of a device according to the invention are shown in a diagrammatic :manner.

Figure 1 by way of example shows a total arrangement. Fig. 2 shows adetail, Figures 3 and 5 relate to a two-stroke and a four-stroke-machine, respectively, Figs. 4, 6 and '7 show several diagrams.

Such a throt- "invention there is no throttling valve arranged at this place, the controlling device (throttle I!) being situated before the generator. In the arrangement according to Fig. l the air is supplied to the generator 4 and the mixing valve 2 by devices (apportioning devices) supplying the gasification air and the combustion air in the proper quantity. In the drawing two rotary pumps 9 and H! are shown serving as apportioning devices, these pumps being driven with a constant speed ratio so that the proportion between the volumes of air fed per time "unit always remains constant and depends on the dimensions and the speed of the pumps. In the form 0! execution shown in the drawings both pumps I and Ill are coupled with one another by chain wheels H and 12 and the chain l3. These rotary pumps suck air through a common pipe ll in which the throttle l5 controlling the .output of the motor is arranged. The air is supplied to the generator 4 and the mixing valve 2. 0f

' course, also separate pipes .could be provided for 7 another.

the pumps 9 and I0, and the throttle 'valves arranged in these pipes could be coupled with one In both'cases the pumps '9 and I0 suck .air of the same specific weight so that the mixing proportion between gas and air always remains constant.

If the speed of the motor remains constant, also the volume :of air sucked in per unit of time remains the same. Therefore by arrangement of the throttle valve 15 before the generator there results that the volume of air flowing through the generator per time unit and there fore also the velocity of flow in the generator remains constant for all outputs because by the adjustment .of the throttle valve l5 only the specific weightof the air, that is to say the pressure, would'be changed.

If, however, the speed of the motor varies, also the sucked volume 10f air or gas per time unit varies. In order to keep the velocity of flow in thegenerator constant, throttle valves I6 and II are arranged in the pipes .5 and I, respectively.

, between the generator 4 .and the mixing valve 2, these valves controlling the pressure in the generator I in such a manner that the volume 0! air flowing through the generator per time unit remains constant under all working conditions. The throttle valves is and I1 are connected by a bar I 8 and a lever l9 witha centrifugal governor -20 so that the valves are moved in the closing sense if the speed gets higher. If the speed of the motor increases, under constant degree of admission and therefore the consumption oi gas increases the pressure in the generator will be increased by the throttling effect oi the valves 16 and 11 to such an extent that notwithstanding the increase in the gas consumption the'volume of air and gas flowing through the-generator per time unit and therefore also :the velocity of flow in the generator remains constant, and vice versa.

The apportioning devices! and l o'keeping up the correct proportion of gas and air maybe driven by the'motor itself or by a separate motor.

Especially if the apportioning devices are driven by the motor the elasticity of the motor is limited. In order to increase the elasticity of the motor throttle valves 23 and 24, respectively, may be arranged in the pipes 2| and 22, respectively, these throttle valves being actuated by the governor through a lever and a bar 26 in such a manner that the throttling effect will be reduced if the speed lowers. In view of the fact that with the maximum speed and the maximum output of the motor a material-throttling must take place, the two apportioning devices 9 and It] must have larger dimensions so that also during such a material throttling they will supply sufiicient gas and air to the motor in correspondence with the required output. The throttling valves 23 and 24 are connected with one another by a bar 21, but also a common throttling device may be arranged in the pipe l4.

The throttling devices arranged between the generator and the motor in order to keep up the Zone of incandescence in the generator-4 as well as the throttling devices arranged before the apportioning devices 9 and ID serving the purpose to increase the elasticity of the motor may be constructed as throttling disks of constant cross section without materially influencing the'effect, and in this case a centrifugal governor becomes superfiuous. Such an arrangement is shown in Fig. 2 in which the adjustable throttling devices l6 and II are replaced by throttling disks 28 and 29. Also the throttling devices 23 and 24 of Fig. 1 may be replaced by such throttling disks.

The use of apportioning devices Q and I0 may be avoided if a motor is used with additional pairs of strokes, which itself carries out the apportioning of both quantities of air during said pairs of strokes. With such a multi-stroke cycle during the additional strokes, first, air is sucked in which during the second stroke of the pair is supplied to the generator 4. Such a process is described in the following in accordance to Fig. 8. Ifa plurality, of pairs of strokes is used a portion of the air sucked in during these pairs is supplied to the generator 4 and the other valve 2 in accordance with tion of the gas-air mixture.

Fig. 3 shows diagrammatically an engine working on the four-stroke-cycle principle, namely as the intended composia common two-stroke motor during two strokes and during the following two strokes as a pump supplying the gasification air to the generator 4. The cylinder head 3! is provided with two valves 3| and 32. Through the valve 3| the air compressed in the cylinder during one of the strokes portion to the mixing when the engine is working as a pump is supplied to the generator 4 as indicated by the arrow 33. The gas generated by the air delivered by the motor to the generator flows from the generator 4 through pipe 5, purifier 6, pipe I back into the cylinder through the valve 32, In the pipes 5 and 1 two throttles I6 and II, respectively, are arranged and operatively connected by rod l8 to the centrifugal governor 2!] in such a Way that they are more closed with increasing speed of the motor, for the purpose described above in accordance to Fig. 1. The piston 34 in its lowermost position opens the exhaust port 35 which is held closed against the exhaust pipe 35 by the valve 31. Furthermore the piston 34in its lowermost position'opens the admission port 38 connected to the compressor of the two-stroke motor. If no compressor is used, but the crank chamber is employed as compressor, the admission port 38 is connected to the crank chamber. The working of this arrangement is more clearly set forth in the diagram shown and described in Fig. 4.

This example shows how apportioning can be carried out by the motor itself. Both quantities of air (one portion for gasification and the other portion for making the mixture) are equally apportioned. By the use of a throttle valve 39, for instance, one can achieve that for instance the admission serving for the generato will by throttling the valve 39 be kept smaller than the other admission remaining in the cylinder so that more air in proportion to the gas will be supplied into the mixing chamber.

Fig. 4 explains by way of a diagram the working of the motor shown in Fig. 3. During the stroke I the piston 34 moves from the upper dead position to the lower dead position. During the stroke the combustion (line 404| and the expansion (line 4l--42) takesplace. When the piston opens the ports 35 and 38 air flows into the cylinder from the compressor or the crank chambe through the port 38 so that the burned gases will be scavenged until the admission of fresh air is finished. This is represented in Fig. 4 by the line 42-43. During the second stroke II during which the .piston moves from the lower dead point to the upper one the admitted air will be compressed in the cylinder (line 43-44) and afterwards is delivered to the generator (line 4445). During the next stroke marked by III the piston moves from the upper to the lower'dead point and the air contained in the compression chamber expands (line 45-46) until the piston opens the ports 35 and 38 so that again air from the compressor or crank chamber will enter into the cylinder (46-41). The exhaust pipe 36 is kept closed by the valve 31.

During the stroke marked by IV, after the piston has closed the ports 35 and 38, the cylinder is connected to the generator and therefore the air supplied .to the generator during thestroke II flows back as gas through the valve 32 into the cylinder, whereby the pressure is increased (41-48). Now the compression follows (line 48-49) and the whole cycle starts again. With such a process twice the quantity of air is available for combustion compared with the common two-stroke motor fed by generator, since the whole cylinder volume is filled with combustion air and the gas is pressed afterwards into the cylinder, While with the common two-stroke-cycle the generator takes up half of the cylinder volume. Therefore the output of such a motor theoretically is equal to the output of a common two-stroke motor of the same speed fed by liquid fuel, liquid fuel taking up only 34% of the cylinder volume. In fact, however, more 'air is available for combustion, because during the second admission of air (line 46-41) the valve 31 is kept closed so that no air is lost.

Also a four-stroke motor with additional pairs of strokes may be used. Such a motor represented in Fig. 5 diagrammatically differs from a common four-stroke motor by the fact that besides the common suction valve 50 two additional valves 52 and 53 are arranged in the'head of the cylinder, the valve 52 controlling the's'up'ply of air from the cylinder to the generator and the valve 53 controlling the inflow of gas from the generator into the cylinder.

Fig. 6 shows the diagram of such a motor working in a six-stroke cycle. These six strokes are marked I-VI in Fig. 6. During the first stroke During the second stroke compression takes place (line 5651) as well as the passing of the air from the cylinder to and the exhaust valve 5| the generator (line 51-58). During the third stmke first the expansion :of the remaining air in the compresssion chamber takes .place (line 58- i!) and afterwards the second admission Of air (line $98il). At the end of the stroke .or the beginning of the next (fourth) stroke the gas from the generator flows back into the cylinder (ill-4|) so that the pressure in point lil of one atmosphere will be increased to two atmospheres (point M Afterwards the mixture is compressed (lb-B2), the combustion (line 62--63), the ex- .pansion (83-44) and the exhaust (line BL-GS') take place in accordance with the working of a. common four-stroke cycle.

Fig. 7 shows the diagram of an eight-stroke cycle motor which will be used for instance if the gas is so poor that one portion of air must be mixed with two portions of gas. In such a case two pairs of strokes are added. The air worked up during these two pairs of strokes is delivered to the generator 4. .If thereafter --i. e. after the fifth stroke orat the beginning of the sixth stroke-the gas flows back from the generator to the cylinder two stroke volumes of gas and on stroke volume of air will be present in the cylinder 50 that the pressure will amount to three atmospheres. Afterwards compression, expansion and exhaust will take place as in common tour-stroke cycles. To simplify the diagram the points in Fig. 7 are marked by the same numerals as in Fig. 6. During the strokes III and IV the process occurring during the strokes I and II is p ated. Therefore, the lines are marked by 55'-56'- lV-JB'.

With the six stroke cycle motor (Fig. 6) the output is 33% greater than with the common iour-stroke cycle motor. With the eight-stroke cycle motor (Fig. '7) the output is 50% greater than with the four-stroke cycle motor because during a six-stroke cycle twice th'e volume of air and during the eight-stroke cycle three times the volume of air is worked up compared with the common four-stroke cycle. In a common fourstroke-cycle there are two suction strokes during eight (two times four) strokes, while in sixstroke-cycle there are only six strokes necessary for two suction strokes. When running at the same speed, the proportion of the strokes necessary for sucking the same quantity of air determines the proportion of outputs In the eight-stroke cycle, on the other hand, there are three suction strokes during eigh't strokes, while according to the common four-stroke cycle twelve (three times four) strokescare necessary for the same number (three) suction strokes. Therefore, the proportion of outputs is This increase in output which is achieved also with a two-stroke cycle motor working in a fourstroke cycle compared with a common two-stroke cycle motor is advantageous because a gas motor has less output than a benzene motor. This, because with a benzene motor the benzene hardly takes up 3-4% of the cylinder volume whereas the normal generator gas takes up belief the cylinder volume and the poor waste gas even moreapproximately two thirds of the cylinder volume. Therefore, even it generator gas is used with the samemotor only 50% and if waste gas is used only v33 of the output can be obtained compared with the use of benzene in .the same motor.

What I claim is:

1. Process of running internal combustion engines fed by generator, at different speeds and different degrees of admission of the motor, consistingin keeping constant the velocity of flow in the generator by throttling the gas flowing out of the generator in such a way that the greater volume 01 gas sucked in by the motor at higher speeds is balanced by a corresponding increase of the pressure in the generator, said increase of pressure being effected by the said throttling, and controlling the gas quantity and air quantity admitted to the motor by simultaneously controlling the supply of air to the motor and air to the generator at a place before the generator the ratio of air fed. to the generator and the motor, respectively, being kept constant.

2. In a process as claimed in claim 1 the throttling of the gas flowing out of the generator being effected in several steps, at a place between the generator and the gas purifying apparatus andat a place between the gas purifying apparatus and the mixing chamber for mixing the gas with the combustion air.

.3. In a process as claimed in claim 1 the throttling of the gas flowing out of the generator being effected in such a manner that with increasing speed the throttling effect is automatically increased by a regulating device.

4. In a process as claimed in claim 1, the air for gasification and the air for combustion being supplied to the generator and the mixing chamber, respectively by devices apportioning the air for gasification in correct proportion to the air for combustion.

5. In a process as claimed in claim 1, consisting in supplying the air for gasification and the air for combustion to the generator and the mixing chamber, respectively by devices apportioning the air for gasification in correct proportion to the air for combustion, the elasticity of the motor being increased by throttling the air in such a manner before entering the appor tioning devices that the throttling effect is increased at high speeds of the motor.

6. In a process as claimed in claim 1, the motor working with supplemental strokes, the air produced during the said supplemental strokes being supplied to the generator as gaslfi- .cation air.

I. In a process as claimed in claim 1, the motor working in two-stroke cycle with supplemental pairs of strokes and the air produced during the said supplemental pairs of strokes, being supplied to the generator as gasiflcation air.

8..In .a process as claimed in claim 1, the motor working a plurality of supplemental pairs of strokes and only a portion of the air produced during the said supplemental pairs of strokes being supplied to the generator as gasification air Whereas the other portion of the air being fed to the motor as combustion air.

9. In a process as claimed in claim 1, the motor working with supplemental strokes, the air produced during the said supplemental strokes being supplied to the generator as gasification air, the mixing proportion between gas and air *being controlled by throttling the suction during the said supplemental pairs of strokes supplying the gasification air to the generator.

10. An apparatus of the character described,

comprising a motor, a generator connected by a pipe with a mixing chamber connected With said motor, means for obtaining a throttling effect at increased speeds of the motor, said means being arranged in the said pipe, another pipe for supplying combustion air to the mixing chamber and another pipe for supplying gasification air to the said generator, rotary piston pumps arranged in the leadings to the generator and to the mixing chamber, respectively, apportioning air to the generator and to the mixing chamber, respectively, in proper portion, said apportioning mean being driven by the motor itself, a centrifugal governor, and throttling means arranged before the said apportioning means and operatively connected to said centrifugal governor in such a way that throttling is increased with increasing speed of the motor, and selectively operable throttling means for controlling the output of the motor arranged before the said apportioning means.

EMIL SCHIMANEK. 

